Butterflyweed (Asclepias
tuberosa L. (Asclepiadaceae)) is a
perennial plant that is found locally on well-drained, open,
calcareous sites throughout the eastern United States. It is a
principal colonizing species within an abandoned limestone quarry
near Syracuse, New York. To determine the direction and rate of
population flux within the quarry, seedling emergence, plant
survival, and reproduction were monitored for six years (1976-1981).
The density of A. tuberosa decreased markedly over the duration of the study.
Sequential droughty years from 1977 through 1979 were most likely the
principal cause of population decline. Moreover, recruitment from
seed was quite low in those years due to seed predation and to rapid
desiccation among newly emergent seedlings. These findings will be
discussed in relation.to the overall process of plant colonization on
severely disturbed sites such as the Syracuse quarry.